1. Technical Field
The technical field relates to surgical staplers, and more particularly to improved anvils for use in surgical staplers of the type in which one or more U-shaped surgical staples are driven through body tissue and against an anvil to deflect, crimp, or clinch the ends of the staple legs and thereby secure the tissue.
2. Background of Related Art
Surgical staplers having a wide variety of configurations are known. In one general type of surgical stapler, the tissue to be stapled is positioned between a staple holding assembly and an opposing anvil assembly, and one or more generally U-shaped staples are driven from the staple holding assembly, through the tissue, and against the anvil to deflect, crimp, or clinch the ends of the legs of the staples and secure the tissue. In relation to forming a staple, the words "deflect", crimp, and "clinch" are used interchangeably herein to refer to deformation of the staple by the anvil. Examples of of surgical staplers having anvils are disclosed in. U.S. Pat. Nos. 4,508,253, 4,520,817, 5,040,715, 5,119,983 and 5,318,221.
In staplers of the general type described above, it is conventional to provide separate anvil slots at each staple forming location. This makes it necessary to maintain relatively stringent alignment between the staple holding assembly and the anvil to assure that the staples enter the anvil slots correctly for proper clinching. It is important that every staple be formed properly since an incompletely or improperly formed staple may leave a gap in a wound closure. The importance of maintaining good alignment between the relatively movable staple holding assembly and anvil assembly may contribute to the complexity of the instrument and to the cost of manufacturing and maintaining it.